From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B521C04AB6 for ; Tue, 28 May 2019 14:58:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1BA8C2133F for ; Tue, 28 May 2019 14:58:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726540AbfE1O6V (ORCPT ); Tue, 28 May 2019 10:58:21 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54426 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726497AbfE1O6V (ORCPT ); Tue, 28 May 2019 10:58:21 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4SEvXiE146422 for ; Tue, 28 May 2019 10:58:19 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2ss4y8pkb2-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 28 May 2019 10:58:19 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 28 May 2019 15:58:13 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4SEwCD545744128 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 28 May 2019 14:58:12 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E050052052; Tue, 28 May 2019 14:58:11 +0000 (GMT) Received: from [9.152.99.121] (unknown [9.152.99.121]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 6B19E52071; Tue, 28 May 2019 14:58:11 +0000 (GMT) Reply-To: mimu@linux.ibm.com Subject: Re: [PATCH v2 8/8] virtio/s390: make airq summary indicators DMA To: Halil Pasic , Cornelia Huck Cc: KVM Mailing List , Linux-S390 Mailing List , Sebastian Ott , Heiko Carstens , virtualization@lists.linux-foundation.org, "Michael S . Tsirkin" , Christoph Hellwig , Thomas Huth , Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman , Pierre Morel References: <20190523162209.9543-1-mimu@linux.ibm.com> <20190523162209.9543-9-mimu@linux.ibm.com> <20190527140018.7c2d34ff.cohuck@redhat.com> <20190528163342.335eea0b.pasic@linux.ibm.com> From: Michael Mueller Organization: IBM Date: Tue, 28 May 2019 16:58:11 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190528163342.335eea0b.pasic@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19052814-0020-0000-0000-000003414827 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19052814-0021-0000-0000-0000219444FF Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-28_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905280097 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 28.05.19 16:33, Halil Pasic wrote: > On Mon, 27 May 2019 14:00:18 +0200 > Cornelia Huck wrote: > >> On Thu, 23 May 2019 18:22:09 +0200 >> Michael Mueller wrote: >> >>> From: Halil Pasic >>> >>> Hypervisor needs to interact with the summary indicators, so these >>> need to be DMA memory as well (at least for protected virtualization >>> guests). >>> >>> Signed-off-by: Halil Pasic >>> --- >>> drivers/s390/virtio/virtio_ccw.c | 22 +++++++++++++++------- >>> 1 file changed, 15 insertions(+), 7 deletions(-) >> >> (...) >> >>> @@ -1501,6 +1508,7 @@ static int __init virtio_ccw_init(void) >>> { >>> /* parse no_auto string before we do anything further */ >>> no_auto_parse(); >>> + summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS); >> >> What happens if this fails? > > Bad things could happen! > > How about adding > > if (!summary_indicators) > virtio_ccw_use_airq = 0; /* fall back to classic */ > > ? > > Since it ain't very likely to happen, we could also just fail > virtio_ccw_init() with -ENOMEM. That is what I'm currently doing in v3. > > Regards, > Halil > > >> >>> return ccw_driver_register(&virtio_ccw_driver); >>> } >>> device_initcall(virtio_ccw_init); >> > Michael